Printed circuit card holder with control and display units

ABSTRACT

A handle for a printed circuit card is provided with a slot for accepting the card, with keyed contacts at the edge of the card projecting into the slot. The card is permanently fastened to the handle by rivets. A plurality of spaced, substantially parallel holes extend through the handle from its front surface to a point of intersection with the slot to expose the contacts on the card. Separate indicator units and control units are slidably received in respective ones of the holes and are frictionally retained therein with spring-loaded terminals of the units electrically contacting the keyed contacts on the printed circuit card. A further array of keyed contacts at the opposite edge of the card is adapted to mate with a female connector when the card is inserted into position in a card shelf, the handle being exposed with legends and indicator units visible thereon and with control units accessible for selective exercise of control on the operation of the circuit carried by the card.

United States Patent Melbourne, Fla.

Appl. No. Filed Patented Assignee PRINTED CIRCUIT CARD HOLDER WITHCONTROL AND DISPLAY UNITS 7 Claims, 12 Drawing Figs.

US. Cl. 317/101 Int. Cl. H021) l/62 Fieldol'Search 317/101, 101 (DH),101(CB); 174/68.5;340/l78, 178.1; 21 1/41; 200/16, 167, 172; 16/(Inquired)References Cited UNITED STATES PATENTS 3/1961 Parkhill et al..3l7/l01C(UX) 9/1962 Scoville 317/101 9/1966 O'Brien ..2D0/166CPC(UX)3,310,710 3/1967 Joachim 317/100 3,349,211 10/1967 Lien ...200/167A(UX)Primary Examiner-David Smith, Jr. Attorney- Donald R. Greene ABSTRACT: Ahandle for a printed circuit card is provided with a slot for acceptingthe card, with keyed contacts at the edge of the card projecting intothe slot. The card is permanently fastened to the handle by rivets. Aplurality of spaced, substantially parallel holes extend through thehandle from its front surface to a point of intersection with the slotto expose the contacts on the card. Separate indicator units and controlunits are slidably received in respective ones of the holes and arefrictionally retained therein with spring-loaded terminals of the unitselectrically contacting the keyed contacts on the printed circuit card.A further array of keyed contacts at the opposite edge of the card isadapted to mate with a female connector when the card is inserted intoposition in a card shelf, the handle being exposed with legends andindicator units visible thereon and with control units accessible forselective exercise of control on the operation of the circuit carried bythe card.

Patented April 6, 1971 2 Sheets-Sheet 1 INVENTUR FRANK DRAPER BRBCOCKHTTDRNEYS Patented April 6, 1971 2 Sheets-Sheet 2 /A/VENTOR FRRNK DRRPERBHBCOCK QTIURNEYS PRINTED CIRCUIT'CARD HOLDER WITH CONTROL AND DISPLAYUNITS BACKGROUND OF THE INVENTION The present invention relatesgenerally to printed circuit boards or cards, and more particularly todevices to permit ease of handling of printed circuit boards forinsertion in and removal from card racks, and to accommodate replaceableindication units and control units for direct electrical and mechanicalconnection to the printed circuit board associated with the device.

It has been typical practice to provide indicators and controlsassociated with the circuit on a particular printed circuit card at alocation or locations remote from the card itself. For example, lampsfor indicating the nature of the circuit operation or the presentoperational state (e.g., on" or off") of a particular portion of thenetwork on a printed circuit card, and manual pushbutton switches forinstituting a change of operational state of that portion of thenetwork, might be located in banks or racks containing a multiplicity ofsimilar indicating and control units associated with other cards forimplementing and detecting an overall system operation. Electricalconnection between these units and the respective cards is accomplishedby soldering wires or leads of appropriate length between terminals withwhich the units and cards are in electrical contact.

The printed circuit card contains a plurality of spaced printed contactsadjacent one edge of the card and keyed to make electrical connectionwith the respective contacts of a mating female connector. This makesfor ease of replacement of cards in large banks, since a defective cardor a card whose function is to be updated need merely be withdrawn fromthe respective connector and a new card, of appropriate function,inserted in its place. Usually, the cards are located in a spacedparallel array in tacks or shelves, the distance between cards beingsufficient to permit accommodation of components such as transistors ordiodes on adjacent cards without inter ference or obstruction. Each cardmay be provided with a handle to simplify handling and replacement ofcards without touching the actual circuitry or components mounted on thecard.

The indication units and control units may be of the plugin type forinsertion into sockets wired to the electrical connec tors for therespective printed circuit cards, but quite often these units arepermanently wired in their banks.

In these prior art arrangements, then, it has been necessary to provideseparate panels for cards and for display and control purposes, leadingto some delay in matching card with indication and/or control unit whenfailures occur in one or both. Moreover, the number of potential sourcesof failure increases in proportion to the number of wiring connections,solder joints, and so forth. Such problems, of course, are in additionto perhaps the most significant disadvantage of the prior art multicardarrangements, namely, that of time-consuming and costly initialinstallation and subsequent replacement.

SUMMARY OF THE INVENTION According to my invention, a card handle orcard holder is provided with a rear slot for receiving and retaining aprinted circuit card, and with several holes running from front to rearand intersecting the slot. The holes are of appropriate size and shapeto accept individual respective display units and control units therein,and the front of each of these units is exposed in the respective handleto permit an identifying designation or symbol with respect to thefunction or circuit relationship of the unit to be imprinted thereon.

Active units retained in a card handle are provided with slots thatregister with the slot in the handle, and that expose spring-loadedelectrical contacts or connectors adapted to mate with printed contactson the card when the card is fully inserted into the handle. Normally,the handle is fastened to the card after the card has been insertedfully into the slot at the rear of the handle. Each card is providedwith what may be termed front edge and rear edge printed contacts, thelatter being standard for electrical connection with a mating femaleconnector when the card is installed for use in a printed circuit cardrack or shelf. The provision of front edge contacts on each card isessential to my invention to permit the aforementioned indication orcontrol units to be pushed into the appropriate hole in the handlewhereupon the spring-loaded contacts on the respective unit accept thematching contacts on the card.

This provides an electrical connection between the circuit printed onthe card and the electrical elements in the unit. Mechanical retentionof each unit is also assured in part by the clamping action of thespring contacts on the card contacts, and further by the provision of atight or frictional fit between the sides of the unit and the walls ofthe hole into which it is to be inserted. Removal of an active unit fromthe handle is effected by withdrawing the handle and card assembly fromits operational position in the card rack or shelf and pushing the unitout from the rear toward the front of the handle.

Passive units are provided in the form of blanks carrying appropriatelegends identifying the function of the unit or its relationship to anassociated piece of apparatus.

In addition to those advantages noted above, it will be observed that notools are required for removal or replacement of a unit; no soldering orother auxiliary fastening procedure is required to establish electricalcontact between printed circuit card and control or display unit; andthe units are disposed immediately adjacent and in direct contact withthe associated card.

A feature of my invention is that the printed circuit cards to whichrespective handles are attached are conveniently mounted in operationalposition in the shelf or rack in a clean, uncluttered panoramicassembly. The handles are juxtaposed along the shelf and are providedwith gripping surfaces to permit ease of removal of the associated cardwithout disturbing adjacent cards or elements mounted thereon. Moreover,each of the units retained in the handle is clearly visible andaccessible to operating and maintenance personnel.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a perspective view of acomplete printed circuit card handle assembly;

FIG. 2 is a fragmentary side view, partly in section, of the assembly ofFIG. 1;

FIG. 3 is a fragmentary top view of the assembly of FIGS. 1 and 2;

FIG. 4 is a sectional view of the handle taken through its longitudinalplane of symmetry and showing a fragmentary portion of the printedcircuit card to be inserted therein;

FIG. 5 is a fragmentary, exploded rear view of the handle card assembly;

FIG. 6 is a perspective view of a control unit for insertion into thehandle of FIGS. 1-5;

FIG. 7 is a rear view of the control unit of FIG. 6;

FIGS. 8 and 9 are side and rear views of a switch constituting a part ofthe control unit of FIGS. 6 and 7;

FIG. 10 is a perspective view of an indicator unit for insertion intothe handles of FIGS. 1-5;

FIG. 11 is a perspective view of a shelf assembly of printed circuitcards with handles; and

FIG. 12 is a section view taken through a shelf of FIG. 11.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIGS. 1 through 5,inclusive, an exemplary printed circuit card handle 10 has asubstantially rectangular blocklike central portion 11 with contouredextensions 12 at either end. A pair of spaced parallel flanges or ribs13 project perpendicularly from the rear surface 14 of handle 10, as isperhaps best viewed in FIGS. 3 and 5, and the flanges are provided witha pair of aligned holes l5, 16 at either end for a purpose which will bediscussed presently. The central region I l of handle 10 is providedwith a plurality of holes l7, l8, l9,

20 (FIGS. 4 and 5) extending entirely through the block from frontsurface 21 to rear surface 14, the holes being of generally rectangularshape. As will subsequently become clear, more or fewer holes may beprovided according to the specific printed circuit card with which thehandle is to be associated.

A gap or slot 22 (FIGS. 3 and 5) formed by the space between flanges 13is carried into the hole area at the rear surface 14 of the handle asslots 23, 24, 25 (FIG. 4) to accommodate a section 26 of a printedcircuit card 30 to be fastened to the handle.

Preferably, handle is composed of heat resistant or fire retardantopaque plastic material and is provided with a fine grain surfacefinish. In practice, the handle is of one-piece construction, formed inits basic shape by any well-known molding process and subsequentlymachined as may be required to provide specific hole and slot tolerancesand to remove any burrs or sharp edges. Flanges 13 need not becontinuous as shown, but may appear at the ends only, and may be taperedat either end, as at 31, to permit some sidewise adjustment of theprinted circuit card 30 during insertion into and assembly with thehandle, as will be discussed. The concave contours 33 at either end ofcentral portion 11 and running smoothly into extensions 12 afford agripping surface, as between thumb and forefinger, during installationand removal of the handle card assembly.

A typical handle produced in accordance with my invention had thefollowing approximate dimensions, presented by way of example only:width (between side surfaces 35 and 36) of 1 inch; depth (between frontsurface 21 and rear surface 14) of 1.0 inch, flange depth of 0.5 inch;body length (from end to end) of 4.3 inches; length of central blockregion (11) of 3 inches; hole width of 0.75 inch; hole length of 0.550,except hole 17 whose length is 0.750 inch; 0.06 radius at corners ofeach hole; material thickness of 0.08 inch between adjacent holes; slotwidth (between flanges 13) of 0.062 inch; slot depth (into hole area ofbody) of 0.25 inch. The mating printed circuit card 30 for handle 10 isof completely conventional design, being provided with conductivecircuit paths and conductive thru-holes and component mounting holes andwith a region of keyed contacts 38 adjacent edge 39, except that card 30is also provided with a further array of keyed contacts 40 at section orregion 26 which is to be the handle end of the card. This region 26 isdesigned to mate and to be inserted into the slot extending into thebody of handle 10 via slot 22 between flanges 13. When the card is soinserted, keyed contacts 40 are registered with those of holes 1720 intowhich active control and display units are to be inserted, and holes 41in the card are aligned with respective hole pairs and 16 in flanges 13.The width of slot 22 is sufiicient to accept the thickness of theinsulative portion of board 30 and of the conductive regions overlyingand adhering to the board surfaces. Typically, the printed circuit cardis approximately 0.054 inch thick. After insertion of card 30 intohandle 10 the two are permanently fastened together by rivets 43 and 44(FIGS. 2 and 3) passing through holes 15 and 16 of flanges I3 and thealigned holes in the card.

As previously observed, a printed circuit card handle according to thepresent invention not only serves as a holder by which to convenientlygrip the card for ease of insertion into and removal from a shelfcomprising a bank of mating female connectors for keyed contacts 38 on aplurality of cards, without directly touching the card itself or thecircuit paths or components thereon, but the handle also serves as anescutcheon and as a means for retaining functional control and displayunits in direct operative relationship with the network on therespective printed circuit card.

A typical control unit 50 is shown in FIGS. 6 through 9 inclusive.Required control may be exercised, for example, by a normally open,momentary pushbutton switch 51 of the single-pole, single throw type.Switch 51 has a flngeror thumboperated pushbutton 52, which, whenactuated, causes a closed circuit path to be completed between one ormore pairs of spring contacts, e.g. 53, 54 disposed at the rear of theswitch. Preferably, these contacts are composed of beryllium copper witha finish of gold plate over nickel, and are so separated (typically, by0.4 inch) on the switch body that they will mate with respective ones ofthe keyed contacts 40 on the printed circuit card when the overallcontrol unit is pushed into its appropriate hole in handle 10. Contacts53 and 54 may be similar to those available from Transitron ElectronicsCorp., Wakefield, Mass, designated as printed circuit contacts series25003. The two contacts constituting a single contact pair (either 53 or54) are approximately 0.04 inch wide, project about 0.3 inch beyond therear surface 55 of the body of switch 51, and are spaced by a distanceand possess a spring constant that a minimum withdrawal force ofapproximately two ounces is required to separate each contact pair fromthe mating contacts of a 0.054 inch thick printed circuit card.

The switch 51 is housed within a control unit casing 57 with pushbutton52 projecting through a hole in front wall 58 and contacts 53 and 54exposed at a slot 59 (typically 0.062 inch wide) in the rear of thehousing, or projecting therefrom. Housing 57 is preferably composed ofheat resistant or fire retardant opaque plastic material, and once theswitch is placed inside and the cover plate (front wall) 58 is replacedthe entire assembly may be maintained separable or inseparable, asdesired. Slot 59 in housing 57 aligns with and matches the width of slot22 in handle 10 when the overall control unit 50 is pushed into anappropriate hole, e.g., hole 20, of the handle. The control unit isdimensioned to encounter a tight (frictional) fit upon insertion intoits respective hole, and this, in conjunction with the spreading open ofthe switch contact sets by the keyed contacts of board 30 as the unit ispushed into the hole to effect electrical connection between switch andprinted circuit, ensures retention of the unit in the handle. Eachactive unit, such as control unit 50, is sufficiently long that itscomplete insertion into the hole results in a secure electricalconnection with the mating contacts of the printed circuit board (FIGS.1 and 2). Fasteners may also be used to retain a unit.

The front wall 58 of the unit may have an overhanging flange or liprelative to the sides of the unit to bottom against front surface 21 ofthe handle, or may simply bottom on (seat against) the printed circuitcard. In either event, this assures that undue force will not beexercised to push the unit into place despite appropriate electricalconnection occurring between switch and board contacts. Moreover, whileremoval of any individual unit from handle 10 may be accomplished bysimply withdrawing the handle and printed circuit card assembly from theshelf in which the circuit card is normally operating, and then turningthe assembly over and pushing the appropriate unit from the rear towardthe front of the handle; a slot 60 (FIGS. 6 and 7) may be provided inthe un derside of the lip, if used, of front wall 58 to permit the unitto be pried loose from the handle without withdrawing the card handleassembly.

A typical display or indicating unit 62 is shown in FIG. 10. The housing57 of display unit 62 is substantially the same as housing 57 of controlunit 50, except that the interior is modified to accept and mount aminiature lamp 63. The pins or leads of lamp 53 are connected to springcontacts 64, 65 of the same type as those described above with referenceto control unit 50. These contacts or terminals may be fixedlypositioned relative to housing 57 and gap 59 by provision of slots (notshown) in which contacts 64, 65 are locked without interfering with thecapability of the contacts to undergo spreading and retraction whenpushed on and removed from the board. The housing of indicator unit 62is composed of transparent or translucent plastic and either the lamp orthe plastic may have an identifying color (e.g., red or green) toindicate the state of the circuit on the associated printed circuitcard. For example, in the overall assembly shown in FIGS. 1 and 2,indicator units 68 and 69, displaying the legends ON and OFF"respectively, might be provided with green and red lamps, respectively.As in the case of the previously described insertion and removal ofcontrol unit 50, each indicator unit is simply pushed into the properhole of handle 10, whereupon its contacts engage the proper contacts ofboard 30, and may be withdrawn by a reversal of that operation. Theholes in the handle position the units and guide them into the contactarea of the associated printed circuit card.

In the case of a switching unit as a control unit 50 for a particularcircuit, actuation of the switch (i.e., turning it on") completes aconnection between otherwise isolated terminals (contacts) on theprinted circuit board, and thereby establishes a circuit connection. Forexample, this may set a logic storage element to provide a signal tocontrol operation of a particular segment of the circuit, and completionof a sequence of operating steps may provide an indicator signal back toan indicator unit 62 to light the respective lamp, as an indication of aparticular operational state of the circuit.

The handle may also accept a passive unit or a blank" 70 (FIGS. 1 and2), which may merely be a faceplate bearing any desired legend to beexposed to view when the blank is inserted into the desired hole, andhaving sufficient material projecting beyond the underside of thefaceplate to ensure retention of the blank in the respective hole (e.g.,17) in handle 10.

An overall assembly of a plurality of printed circuit cards withattached handles in an operational shelf or rack is shown in FIG. 11,and a section through the shelf is shown in FIG. 12. Shelves 75 and76are merely two of several such shelves arranged in a vertical bay, forexample, to mount a large number of printed circuit cards in electricalconnection with a similar number of mating female connectors (not shown)mounted at the rear of each shelf. The cards are inserted intorespective guides 77 at top and bottom of each shelf as may be observedby reference to shelf 75 from which the cover has been removed to showsome of the detail of the frame. Each card is inserted and withdrawn byits respective handle, the handles 10 being in juxtaposed relationshipalong each shelf and providing sufficient spacing between cards toprevent interference between circuit components mounted on adjacentcards. A cover 78 is shown as retained on the frame of shelf 76, thecover having an opening of sufficient extent to expose every handleon'that shelf, and thereby to visually display the legends on the unitsand the indicator units associated with each handle and to provideaccess to the control units.

lclaim:

l. A printed circuit card holder for retaining a card having keyedterminals associated with the printed circuit carried by said cardadjacent at least two edges of said card, said holder comprising:

an electrically insulative body member having four sides, opposite pairsof which are substantially parallel to one another, and having two ends;

a pair of electrically insulative ribs projecting in spaced parallelrelation from and substantially perpendicular to one of said sides ofsaid body and defining a slot therebetween of width sufficient to acceptthe thickness of said printed circuit card and the thickness of theprinted circuit carried by said card, said slot extending partly intosaid body member at said side from which said ribs project;

a plurality of spaced substantially parallel holes extending throughsaid body member from the side opposite said side from which said ribsproject and intersecting the portion of the slot extending into saidbody;

a printed circuit card in said slot and fastened to said ribs with thekeyed terminals at one edge of said card exposed in at least some ofsaid holes intersecting said slot; and

control and display means mating with respective ones of said some ofsaid holes and having electrical connectors electrically contactingkeyed terminals at said one edge of said card for electrical interactionwith the circuit carried by said fastened card.

2. The card holder according to claim 1 further including a surfacecontour at each of said ends to facilitate gripping of the holder fortransfer of the assoclated card from one position to another.

3. The card holder according to claim 1 wherein said control and displaymeans are slidably insertable into and slidably removable from saidholes.

4. A printed circuit card holder for retaining a card having keyedterminals associated with the printed circuit carried by said cardadjacent at least two edges of said card, said holder comprising:

an electrically nonconductive handle having a front edge and a rearedge;

a slot in said rear edge of said handle sufficiently wide to accept aprinted circuit card;

a plurality of spaced-apart holes extending in a substantially parallelarray through said handle from said front edge to said rear edge andintersecting said slot;

a printed circuit card fastened in said slot with the keyed terminalsalong one edge of said card projecting toward said front edge of saidhandle and exposed in at least some of said holes intersecting saidslot; and

a plurality of control and display means slidably engaged in respectiveones of said some of said holes, via said front edge of said handle forselective withdrawal from said front edge, and having electricalconnectors electrically contacting the keyed terminals at said one edgeof said card exposed in said holes for electrical interaction with thecircuit carried by the fastened card, said control and display meansbeing fixedly mounted relative to said card for electrical operationtherewith and said electrical connectors continuously contacting therespective keyed terminals at said one edge of said card.

5. The combination according to claim 4 wherein said control meanscomprises switch means for selectively electrically connecting anddisconnecting portions of the circuit carried by said card via therespective keyed terminals with which the electrical connectors of therespective control means make contact.

6. The combination according to claim 4 wherein said display meanscomprises indicator means for detecting and dis playing the operatingstate of a portion of the circuit coupled to the respective keyedterminals with which the electrical connectors of the respective displaymeans make contact.

7. The combination according to claim 4 wherein said control meanscomprises means for selectively modifying the operation of the circuitcoupled to the respective keyed terminals with which the electricalconnectors of the respective control means make contact.

1. A printed circuit card holder for retaining a card having keyedterminals associated with the printed circuit carried by said cardadjacent at least two edges of said card, said holder comprising: anelectrically insulative body member having four sides, opposite pairs ofwhich are substantially parallel to one another, and having two ends; apair of electrically insulative ribs projecting in spaced parallelrelation from and substantially perpendicular to one of said sides ofsaid body and defining a slot therebetween of width sufficient to acceptthe thickness of said printed circuit card and the thickness of theprinted circuit carried by said card, said slot extending partly intosaid body member at said side from which said ribs project; a pluralityof spaced substantially parallel holes extending through said bodymember from the side opposite said side from which said ribs project andintersecting the portion of the slot extending into said body; a printedcircuit card in said slot and fastened to said ribs with the keyedterminals at one edge of said card exposed in at least some of saidholes intersecting said slot; and control and display means mating withrespective ones of said some of said holes and having electricalconnectors electrically contacting keyed terminals at said one edge ofsaid card for electrical interaction with the circuit carried by saidfastened card.
 2. The card holder according to claim 1 further includinga surface contour at each of said ends to facilitate gripping of theholder for transfer of the associated card from one position to another.3. The card holder according to claim 1 wherein said control and displaymeans are slidably insertable into and slidably removable from saidholes.
 4. A printed circuit card holder for retaining a card havingkeyed terminals associated with the printed circuit carried by said cardadjacent at least two edges of said card, said holder comprising: anelectrically nonconductive handle having a front edge and a rear edge; aslot in said rear edge of said handle sufficiently wide to accept aprinted circuit card; a plurality of spaced-apart holes extending in asubstantially parallel array through said handle from said front edge tosaid rear edge and intersecting said slot; a printed circuit cardfastened in said slot with the keyed terminals along one edge of saidcard projecting toward said front edge of said handle and exposed in atleast some of said holes intersecting said slot; and a plurality ofcontrol and display means slidably engaged in respective ones of saidsome of said holes, via said front edge of said handle for selectivewithdrawal from said front edge, and having electrical connectorselectrically contacting the keyed terminals at said one edge of saidcard exposed in said holes for electrical interaction with the circuitcarried by the fastened card, said control and display means beingfixedly mounted relative to said card for electrical operation therewithand said electrical connectors continuously cOntacting the respectivekeyed terminals at said one edge of said card.
 5. The combinationaccording to claim 4 wherein said control means comprises switch meansfor selectively electrically connecting and disconnecting portions ofthe circuit carried by said card via the respective keyed terminals withwhich the electrical connectors of the respective control means makecontact.
 6. The combination according to claim 4 wherein said displaymeans comprises indicator means for detecting and displaying theoperating state of a portion of the circuit coupled to the respectivekeyed terminals with which the electrical connectors of the respectivedisplay means make contact.
 7. The combination according to claim 4wherein said control means comprises means for selectively modifying theoperation of the circuit coupled to the respective keyed terminals withwhich the electrical connectors of the respective control means makecontact.